Temp: Aim it right in the center of the thermostat covers (at the top of each cylinder head) for best results.
TPS: Should be set at .95-.98 VDC (and setting proceedures are covered in the OEM Mercury Repair Manual). A TPS test harness is recommended for this proceedure.
Injectors: "Replaced" is pretty relative.... were they new, used, or ???
Plugs: Don't arbitrarily start changing plugs or heat ranges- results aren't always good for the engine. Stick with the plugs DESIGNED for the engine for best/safest results.![]()